Does ATF work if I play it first, THEN play other plot twists?

If the card says "play only if you have played no other plot twists this turn" and does not say "you can not play plot twists this turn" after the effect, then that is correct.

I think it goes something like: If no other plot twists have been played this turn, characters named Superman or Batman you control get +2/+2 this turn.

"If you have played no other plot twists, etc"

The wording template is to prevent you from playing multiple At their Finest in one turn.

If it was wording "if no other plot twists have been played" then your opponent could play a PT like Flying Kick in response to negate your effect...

~JP